1. Field of the Invention
This invention relates to an automatic ghost-suppression system for use in a television receiver or more particularly to an automatic ghost-suppression system in which a ghost contained in a vertical blanking period of a video signal is detected by means of adding the video signal directly applied to an adder and the video signal applied to the adder through a variable delay device and a polarity and gain control device (hereinafter referred to as a ghost-suppression signal), and the detected ghost is used as a control signal for automatically controlling the polarity and gain control device.
2. Description of the Prior Art
A conventional ghost-suppression system for use in a television receiver is well known in which part of a demodulated receiving signal (a video signal) is delayed and adjusted in its polarity and amplitude so as to permit a ghost contained in the video signal to be offset when its delayed part is added to the video signal thereby to suppress the ghost. In such a system, the delay time and the polarity and amplitude of the delayed signal are required to be adjusted. Those adjustments are currently performed manually, often resulting in an incomplete adjustment. In addition, it is very difficult to improve the condition of incomplete adjustment because of the fact that it cannot be seen from the screen which adjustment for polarity or gain is needed.